Cooling system for internal-combustion engines



Sept. 14, 1948.

COOLING Fil ed Nov. 4, 1946 P. w. EELLS 2,449,110 SYSTEM FOR INTERNAL-COMBUSTION ENGINES 2 Sheets-Shet 1 Q Z0. 6266M P. W. EELLS Sept. 14, 1948.

COOLING SYSTEM FOR INTERNAL-COMBUSTION ENGINES Filed Nov. 4, 1946 2 Sheets-Sheet 2 INVENTOR.

@ZwaQM (9770/F/VE'V45'.

Patented Sept. 14, 1948 COOLING SYSTEM FOR INTERNAL- COMBUSTION ENGINES Paul w. Eat, West Allis, Wis., nssignor to Le Roi Company, West Allis, Wis., a corporation of Wisconsin Application November 4, 1946, Serial No. 707,655 9 Claims. (Cl. 123-174) This invention relates generally .to improvements in the art of heat exchange, and relates more specifically to improvements in the con struction and operation of cooling systems for internal combustion engines or the like.

The primary obiect of my invention is to provide an improved cooling system for internal combustion engines or the like. which is sim le in construction and highly efiicient in operation.

Ordinarily. internal combustion engines employing vaporizing and condensing cooling s stems. have the r cylinders surrounded b a water jacket in open communication at the to with a vapor condenser embodying either vertical or horizontal heat radiating tubes through which the vapor may flow internally and past which cool ng air may be circulated or propelled externally by a fan or blower. When vertical radiation tubes are utilized in such condensers, the condensate must return to the water jacket in direct opposition to the rising vapor, thus causing both the condensate and the vapor to impede each others progress and also permitting the condensate to form an insulating layer or coating on the interiors of the tubes. When the radiat on tubes are disposed horizontally or nearly so, the condensate accumulates in large quant ties upon the lower internal tube surfaces and does not gravitate quickly toward the cooling water jacket, thus likewise providing relatively deep insulating basins of liquid in the tubes which prevent most effective heat transfer. Then too. in both 01' these prior vertical and horizontal tube condensers, it is very diflicult to properly direct the cooling air along and between the nests of tubes in a manner whereby most efficient condensation of the vapor is accomplished, thus making them relatively objectionable for various reasons.

It is therefore a more specific object of the present invention to provide an improved cooling system of the vaporizing and condensing type, wherein the condenser tubes are disposed so as to most effectively condense the vapor and to permit free return of the condensate to the heat absorbing jacket of an engine with minimum obstruction to the vapor and condensate flows.

Another specific object of this invention is to provide an improved cooling system for internal combustion engines of the water cooled type and having a cooling air blower for the water driven by the engine so as to deliver the air laterally of the engine shaft, wherein the air is most eilectively applied for water cooling and vapor condensing purposes without necessitating the use of complicated deflectors for the air flow.

A further specific object of the invention is to provide a cooling system for internal combustion engines or the like, having an improved vapor condenser disposed and associated therewith in a manner whereby most efiicient radiation of excess heat is constantly effected during normal operation of the engine.

Still another specific object of my invention is to provide an improved vapor condenser 01' thetubular type, wherein the tubes are so formed and positioned at an oblique angle to the direction of flow of the rising vapor and of the returning condensate produced in the condensing unit, that most efiective cooling is assured at all times.

An additional specific object of the invention is to provide an improved water cooled internal combustion engine and cooling system therefor, wherein the engine, tubular vapor condenser, and cooling air circulating fan or blower. are compactly associated with each other to produce a single relatively small power generating unit of maximum capacity and efficiency. I

These and other objects and advantages of the invention will be apparent from the following detailed description. i

A clear conception of the features constituting my present improvement, and of the construction and operation of a typical internal combustion engine and cooling unit embodying such features, may be had by referring to the drawing accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

Fig. 1 is a perspective view of a typical commercial internal combustion engine embodying my improved vaporizing and condensing cooling system;

Fig. 2 is an enlarged longitudinal section through the improved inclined tubular vapor condenser of the cooling system, also showing a fragment of the cooling water jacket;

Fig. 3 is a similarly enlarged transverse section through the improved condenser, showing the tube formation and arrangement;

Fig. 4 is a somewhat diagrammatic side view of the combined engine, condenser, and blower unit; and

Fig. 5 is a similarly diagrammatic end view of the same unit, looking directly toward the blower inlet.

While the invention has been shown and described herein as being advantageously applicable to a particular type of internal combustion engine cured at their lower ends to a tube direct connected to a particular type of air circulating blower, it is not my desire or intention to unnecessarily limit the scope or to restrict the utility of the improvements by virtue of this specific embodiment.

Referring to the drawing, the typical power generating unit disclosed therein, comprises in general an internal .combustion engine 8 having one or more cylinders 9 surrounded by a cooling liquid or water jacket l0, and also having a horizontal main shaft ll operable by the engine pistons to deliver 'power to any desired point of utilization; a vapor condenser l3 having a group of parallel inclined laterally spaced tubes 14 sesheet or plate [5 which is mounted upon a base casing l8 forming a chamber I! in open communication with the cylinder jacket ii), the tubes [4 also being in open communication with each other at their upper ends through an upper end head l8, and the group being confined between opposite side plates l9 forming an air duct between the spaced tubes; and a blower 2i having a bladed rotor 22 direct connected to the engine shaft l l, and being provided with a casing 23 secured to the engine 8 and having an axial horizontally directed screened inlet opening 24 and a tangential upwardly directed discharge duct 25 within which the inclined condenser 13 is bodily confined.

The engine 8 is mounted upon a base 2! which supports the entire unit, and the water confining jacket I is normally filled with liquid and in constant communication with the chamber I! through a large opening 28 as clearly shown in Fig. 2. The inclined tubes M of the improved condenser l3, are preferably of approximately elliptical transverse cross-section with the major axes of the ellipses disposed in vertical planes as depicted in Fig. 3; and the lower ends of these tubes I 4 extend slightly beyond the tube sheet i and are firmly secured thereto, while the upper extremities thereof are likewise firmly secured to the end head l8. The upper end head It! is also provided with a suitable excess pressure relief valve 29, and the side plates l9 firmly unite the upper head IS with the lower plate l5 and are secured to the adjacent walls of the air duct 25 by means of screws 30, or otherwise. The condenser unit is additionally supported from the base casing 16 by means of screws 3| connecting the lower plate IS with the top of the casing [6. The inlet opening 24 of the blower 2| may be provided with a screen as illustrated in Figs. 4 and 5. but the interior of the air discharge duct is preferably devoid of deflectors and obstructions to the air flow, other than the condenser tubes I in order that free and direct contact of practically all cooling air with the radiator tubes will be assured.

During normal operation of the typical improved cooling system shown in the drawings, the internal combustion engine 8 is functioning to deliver power to the main shaft II, and to simultaneously revolve the annular bladed rotor 22 of the blower 2|, and the rotor blades are then drawing cooling air in abundant quantities through the inlet opening 24 and are constantly delivering this air from within the casing 23 into the discharge duct 25 and past the inclined radiation tubes l4. Continued operation of the engine 8 causes the liquid within the jacket ill to become heated to such an extent that vapor is generated and rises through the opening 28 and through the chamber ll into the inclined radiation tubes II, and the rising vapor constantly tends to fill these tubes. The vapor thus delivered into the tubes M will however be promptly condensed by the cooling air flowing between and along the tube exteriors, and the condensate will collect at the lowermost inclined bottom portions of the several tubes and will drain by gravity along the valleys formed by these tube bottoms, evenually being returned to the jacket l0 through the chamber H in the form of liquid drops, as indicated in Fig. 2. This cooling cycle involving continuous vaporization of liquid and condensation of the vapor, will continue as long as the internal combustion engine remains in operation; and if for any reason, the pressure within the jacket l0, chamber I! or condenser l3 becomes excessive, the relief valve 29 will promptly and automatically release such pressure into the duct 25 and from thence into the ambient atmosphere.

The improved coollng system has several important advantages over prior systems involving vaporizing and condensing cycles, and-which are attained by the use of the inclined condenser or radiation tubes l4. One of these advantages is that the condensate produced in the inclined tubes 14 and which returns by gravity to the engine jacket 10, flows downwardly along the lower inclined bottoms or valleys of the several tubes, leaving the major upper interior tube surfaces free of liquid films and available for direct contact and most effective condensation of the vapor rising through the tube interiors. With the inclined disposition of the tubes the liquid droplets produced by condensation, flow at an angle relative to the direction of flow of the rising vapor, and quickly collect only in the bottoms or lowermost tube portions, thus preventing insulating liquid coatings from gathering upon the greater internal surface areas of the tubes, especially when tubes of elliptical cross-section are utilized.

Then too, the angular or inclined disposition of the radiation tubes permits freer and more uniform flow of the cooling air over and along the external surfaces of tubes I 4 of various types. In practice, the tubes 14 are frequently provided with external fins or projections in order to increase their exterior radiating surfaces, and these fins are ordinarily disposed approximately perpendicular to the tube axes so as to direct the air flow across the tube assemblages. Either finned or plain tubes i4 may be utilized in the improved inclined condenser i3, and when such a condenser is used in connection with a blower 2i of the type shown in the drawing wherein the rotor 22 is revolved directly by the engine 8 and delivers the air tangentially and upwardly, the air flow will be delivered uniformly and directly through the eX- ternal passages between the tubes l4, without resorting to the use of obstructive baflles and other complicated air fiow deflectors. The inclined condenser uni-t I3 may obviously be readily mounted within the blower discharge duct 25 with the aid of the screw 3|] shown in Figs. 1 and 2 so that the air flow need not be sharply or excessively diverted before it contacts the heat transfer surfaces, thus not only simplifying the assemblage, but also increasing the quantity of air available for cooling.

From the foregoing detailed description it will be apparent that my present invention provides an improved cooling system for internal combustion engines or the like, which besides being simple and compact in construction, i also highly emcient in operation. The inclined disposition of the condenser tubes ll when utilized in a system involving the vaporizing and condensing cycle. insures most effective condensation of the vapor and return of the condensate to the cooling jacket ll, surfaces of-the tubes are maintained free of insulating liquid films or coatings. while the tube inclination permits rapid flow of the condensate by gravity to the source of vaporization of the liquid. This incl ned tube assemblage when employed in such cooling systems also eliminates undesirable obstruction to the flow of the heat transfer fluid. and may be advantageously utilized in cooling units utilizing either air. water or. other liquids as heat transfer media. 'I'he im roved system is especially adaptable to cooling units for internal combustion engines direct connected to blowers or pumps for circulating the heat transfer med a. by virtue of the fact that it permits direct and most effective application of the cooling fluid to the condensing tube with minimum obstruction and change of direction: and the entire system may obviously be embodied in a 'single compact unit capable of being readily transported and installed in limited quarters. The invention has proven highly satisfactory and successful in actual use, especially as applied to a power generating unit such as illustrated, but may also be advantageously utilized in other types of internal combustion engines.

It should beunderstood that it is not desired to limit this invention to the exact details of con struction or to the precise mode of operation of the system herein specifically shown and described, for various, modifications within the scope of the appended claims may occur to persons skilled in the art. It is also intended. that specific descriptive terms used herein, be given the broadest possible interpretation and meaning possible and consistent with the advantageous application of the improvements.

Iclaim: I 1. In a liquid vaporizing and condensing system for cooling a heat engine, a condenser having radiation tubes abruptly inclined and directed toward the engine heat generating zone to cause condensate to gravitate rapidly along the lowermost internal tube surfaces toward said zone, said jtubes having elliptical transverse cross-sections with the major axes of the ellipses lying in vertical planes, and means operable by the engine for delivering cooling medium externally across said tubes without abrupt change in the direction of flow of the medium.

2. In a liquid vaporizing and condensing system for cooling a heat engine, a condenser having radiation tubes abruptly inclined and directed toward the engine heat generating zone to cause condensate to gravitate rapidly along the lowermost internal tube surfaces toward said zone, said tubes having elliptical transverse cross-section with the major axes of the ellipses lying in vertical planes, and means operable by the engine for delivering cooling medium externally across said tubes in a direction parallel to said planes and without obstruction to the-flow of the medium after leaving said delivery means.

3. In a liquid vaporizing and condensing system for coolingan internal combustion engine, a

by virtue of the fact that the malor internal sate to gravitate freely along the lowermost internal tube surfaces toward said jacket. and means operable directly by the engine for delivering cooling medium externally across said tubes while avoiding abrupt change in the direction of flow of the medium.

4. In a liquid .vaporizlng and condensing sysfor cooling an internal combustion engine, a condenser having a group of radiation tubes abruptly inclined and directed toward and in open communication with the engine cooling jacket, said tubes having vertically elongated elliptical transverse cross-sections so as to cause condensate to gravitate freely along the lowermost internal tube surfaces toward said Jacket, and an impeller rotatable directly by the engine for de-- livering cooling medium externally across said tubes along vertical planes and without obstruction to the flow of the medium after it leaves the impeller.

5. In a liquid vaporizing and condensing system for cooling an internal combustion engine, an air blower operable directly by the engine and having an air delivery duct extending away from the engine shaft, and a condenser having a group of spaced tubes spanning said duct adjacent to said blower, said tubes being abruptly inclined relatively to said shaft and directed toward and in open communication Jacket to cause condensate to gravitate freely along the lowermost internal tube surfaces toward said jacket.

6. Ina cooling system for an internal combustionengine having an approximately horizontal shaft, an air blower directly operable by the engine shaft and having an upwardly directed air delivery duct. and a condenser having a group of spaced tubes spanning said duct directly above said blower. said tubes being inclined toward'and in open communication with the upper portion of the engine cooling jacket.

7. In a cooling system for an internal combustion engine having an approximately horizontal shaft, a condenser having a group of parallel spaced tubes inclined downwardly toward the engine cooling jacket and in open communication therewith, and an air blower having a rotor driven directly by the engine shaft and being provided with an upwardly directed air delivery duct formed to deliver air without abrupt change in direction to the spaces between the tubes of said roup, said condenser being detachably confined entirely within said duct.

8. In a cooling system for an internal combustion engine having an approximately horizontal shaft, a condenser having a group of parallel spaced tubes inclined downwardly toward the engine cooling jacket and in open communication therewith, and an air blower having a rotor driven directly by the engine shaft and being provided with an upwardly directed air delivery duct formed to deliver air without abrupt change in direction to the spaces between the tubes of said roup, the tubes of said condenser having elliptical transverse cross-section with the major axes of the ellipses lying parallel to the direction of flow of the air through said spaces.

9. In a liquid vaporizing and condensing systern for cooling a heat engine, a condenser havcondenser having a group of radiation tubes abruptly inclined and directed toward and in open communication with the engine cooling jacket, said tubes "having vertically elongated'elliptical transverse cross-section so as to cause condenwith the engine cooling I planes, and means for delivering cooling medium Number externally across said tubes in a vertical direction. 1,182,825 PAUL W. EELLS. 1,431,965 1,432,518 REFERENCES CITED 5 1,553,808 The following references are of record in the file of this patent:

Number UNITED STATES PATENTS 404,517 Number Name Date 10 714,445 Bridson et a] Nov. 25, 1902 Name Date Wedderburn May 9, 1916 Livingston Oct. 17, 1922 Armstrong Oct. 17, 1922 Eriksson Sept. 15, 1925 FOREIGN PATENTS Country Date England 1934 

